The invention described herein may be manufactured and used by and for the Government of the United States of America for Governmental purposes without the payment of any royalties thereon or therefor.
(1) Field of the Invention
The invention relates to submarine underwater countermeasures assemblies and is directed more particularly to an improved countermeasure vehicle.
(2) Description of the Prior Art
In FIG. 1, there is shown a typical submarine countermeasure apparatus 20. The apparatus 20 includes a launch tube 22 which, in operation, is disposed outboard of the submarine pressure hull (not shown). A countermeasure vehicle 24 is housed in the launch tube 22 and includes an array assembly 26 and a tailcone assembly 28. The array assembly 26 is protected by a surrounding sabot 30. Disposed in the launch tube 22 is a ram plate 32 and a gas generator 34. The launch tube 22 is closed by a forward tube cover 36 and an after tube cover 38.
In operation, the gas generator 34 is activated by an electrical pulse from the submarine fire control system and generates sufficient gas pressure to move the ram plate 32 forward. The ram plate 32 in turn pushes the countermeasure vehicle 24 forward, breaking away the forward tube cover 36 and launching the countermeasure vehicle 24 from the launch tube 22. In short order, the sabot 30 disengages from around the array assembly 26 and the array assembly is deployed.
The tail cone assembly 28 includes a propulsion propeller assembly (not shown in FIG. 1), and the countermeasure vehicle 24 houses a motor (not shown in FIG. 1) which drives the propeller to position the countermeasure in a column of water.
It has been found that upon launch of the vehicle 24, a combination of a high velocity launch, high forward speed of the submarine, and strong underwater currents, can subject the propeller blades to pressures and bending moments sufficient to damage the blades. Damaged propeller blades can adversely affect the ability of the countermeasure to hover at a selected depth in the water column, and thereby cause mission failure which places the submarine in a state of increased danger.
Accordingly, there is a need for an improved propeller assembly which can withstand and survive the aforesaid launch conditions and assume operations leading to a successful mission.
An object of the invention is, therefore, to provide an improved submarine countermeasure vehicle, featuring a propulsion assembly having facility to withstand the rigors of a launch and provide the propulsion needed to successfully complete a mission.
With the above and other objects in view, as will hereinafter appear, a feature of the present invention is the provision of a submarine countermeasure vehicle comprising an elongated body for supporting a countermeasure device, and a propulsion-assembly mounted on an after end of the body. The propulsion assembly comprises a rotatable propeller hub, propeller blades mounted on the hub and moveable between a first position wherein the blades extend substantially radially outwardly from the hub, and a second position wherein the blades extend generally axially of the hub. A spring is mounted on each of the blades and in the hub, the spring biasing the blades toward the first position, but of sufficient flexibility to permit the blades to move to the second position upon launch of the vehicle from an underwater launch tube.
The above and other features of the invention, including various novel details of construction and combinations of parts, will now be more particularly described with reference to the accompanying drawings and pointed out in the claims. It will be understood that the particular device embodying the invention is shown by way of illustration only and not as a limitation of the invention. The principles and features of this invention may be employed in various and numerous embodiments without departing from the scope of the invention.